CI: lock cargo-cache to use the same deps as the project to avoid rust compiler incompatibilities

Author: nyetwurk

.github/workflows/test.yml

@@ -39,7 +39,10 @@ jobs:
           components: rustfmt, clippy
 
       - name: Install cargo-cache
-        run: cargo install cargo-cache
+        # Use --locked to pin to the exact dependency versions in cargo-cache's Cargo.lock
+        # This prevents pulling in newer transitive dependencies (like home@0.5.12)
+        # that require rustc 1.88, ensuring compatibility with our rustc 1.86 toolchain
+        run: cargo install cargo-cache --locked
 
       - uses: actions/cache@v3
         with: